Bleeding Compressor

Whilst not directly relevant to the original question in this thread I do have some related points.

I use an old fridge compressor in my workshop more or less exclusively just feeding a small nozzle (blowgun). Rather than have a have a reservoir I just switch the compressor on and off as required.

Water is not a problem but although I have used this same compressor for about 10 years, oil from its internal lubrication reservoir is emitted as a fine mist the first time the compressor is used each day.

I have no idea how much oil there things contain but I am amazed that there is any left after 10 years.

Ian P

PS. I know the regulations regarding recycling refrigeration equipment but this compressor was salvaged from a fridge that had leaked all its CFCs before I got it.

Ian P

Ian,

Its a bit like owning a British motorcycle, all the time it leaks oil you know it has oil in it, when its stops thats the time to top it up

Martin P

Here's the drawing for the auto drain valve.

[URL=http://s1149.photobucket.com/user/steamdave/media/Auto%20drain%20valve.jpg.html][IMG]http://i1149.photobucket.com/albums/o591/steamdave/Auto%20drain%20valve.jpg[/IMG][/URL]

Dave
The Emerald Isle

Hi Dave,
Does this work because the ball exerts slightly less downward force when surrounded by water ? Do you have to carefully adjust the spring tension and weight of the arm to set it up. This is dave's link

Les.

Air pressure keeps the ball on its seat. So the spring has to be strong enough to lift the ball when the air pressure drops. Stronger spring, higher air pressure that lifts the ball.

With a length of only 1", the manual operating lever will have very little effect on the operating pressure.

The actual pressure that allows the ball to lift is a personal choice and can be adjusted by the installer. And this takes into account any water that may be in the air reservoir. Instead of stretching the spring to increase the operating pressure, the spring seat can be made overlong and trimmed back until satisfactory conditions prevail.

Dave
The Emerald Isle

going back to an earlier post, i also have experienced a drain blocking. i found it was years of accumulated 'crud'. i just cleared the hole with a probe, whereupon the air was able to blow more stuff out. it seemed to clear eventually, and now will blow air until empty or i close it. i was pleased to see that there was no rust particles ejected. (the compressor was a mates 'spare' until he got sick of tripping over it and gave it to me...)

May I return to the worrying issue of internal corrosion?

I've had a small (1.5 HP) compressor for about 20 years in my home workshop and it gets intermittent use. Every time I've finished using it, I allow the pressure to drop to about 15 psi and slowly undo the drain plug as one might do with a loco boiler blow down.

An appreciable amount of clear water freezes around the plug which I've assumed is water vapour from the resevoir. The plug is always removed until the compressor is needed agian. The resevoir is presumably mild steel and like other users, internal rusting has always been an anxiety. Despite searching, I've not found any information about the life expectancy of these 'little' compressors, or rather, their resevoirs. I've been told I shouldn't worry about catastrophic faliure, rusting would just lead to pin holes at first !

Has anyone sound advice to offer please?

<>

Use of old fridge compressors in the workshop should probably be discouraged once the special lubricant (e.g Emkarox) has been lost. They are designed to operate in closed systems with constant lubrication. When run dry they can overheat dangerously. But, yes, there are many which have been used at high CFM for some years but I'd rather use a 'proper' compressor nothwithstanding the corrosion concers,

Every time I see "bleeding Compressor" in the topics listing, I read it as an expletive

If you needed any top up oil or to replace it - Jun-Air synthetic SJ-27F would do the job. I've only come across this recently - not aware of other types of brands of small compressor oil although I'm sure they exist . On the down side this ain't cheap but will last a long time. (Normal disclaimer)

John

Edited By Johnboy25 on 23/05/2015 06:24:44